Port char-width

rust_src/src/character.rs

@@ -3,6 +3,7 @@
 use libc::{c_uchar, ptrdiff_t};
 
 use remacs_macros::lisp_fn;
+use crate::remacs_sys::{char_width, buffer_display_table};
 
 use crate::{
  lisp::LispObject,
@@ -26,6 +27,16 @@ pub const fn char_head_p(byte: c_uchar) -> bool {
  (byte & 0xC0) != 0x80
 }
 
+/// Return width of CHAR when displayed in the current buffer.
+/// The width is measured by how many columns it occupies on the screen.
+/// Tab is taken to occupy `tab-width' columns.
+/// usage: (char-width CHAR)
+#[lisp_fn(c_name = "char_width", name = "char-width")]
+pub fn char_width_lisp(ch: Codepoint) -> isize {
+ let width = unsafe { char_width(ch.val() as i32, buffer_display_table()) };
+ width
+}
+
 /// Decrement the buffer byte position `POS_BYTE` of the current buffer
 /// to the previous character boundary. No range checking of POS.
 ///

src/character.c

@@ -95,22 +95,6 @@ char_width (int c, struct Lisp_Char_Table *dp)
 }
 
 
-DEFUN ("char-width", Fchar_width, Schar_width, 1, 1, 0,
- doc: /* Return width of CHAR when displayed in the current buffer.
-The width is measured by how many columns it occupies on the screen.
-Tab is taken to occupy `tab-width' columns.
-usage: (char-width CHAR) */)
- (Lisp_Object ch)
-{
- int c;
- ptrdiff_t width;
-
- CHECK_CHARACTER (ch);
- c = XINT (ch);
- width = char_width (c, buffer_display_table ());
- return make_number (width);
-}
-
 /* Return width of string STR of length LEN when displayed in the
  current buffer. The width is measured by how many columns it
  occupies on the screen. If PRECISION > 0, return the width of
@@ -531,7 +515,6 @@ syms_of_character (void)
  staticpro (&Vchar_unify_table);
  Vchar_unify_table = Qnil;
 
- defsubr (&Schar_width);
  defsubr (&Sstring);
  defsubr (&Sunibyte_string);
  defsubr (&Sget_byte);

test/rust_src/src/fns-tests.el

@@ -36,6 +36,12 @@
  (should (equal (make-char-table 'syntax-table '(3))
  (make-char-table 'syntax-table '(3)))))
 
+(ert-deftest test-equal-char-width ()
+ (should (equal (char-width ?a) 1))
+ (should (equal (char-width ?1) 1))
+ (should (equal (char-width ?\n) 0))
+ (should (equal (char-width ?你) 2)))
+
 (ert-deftest test-equal-vector ()
  (should (equal [1 two '(three) "four" [five]]
  [1 two '(three) "four" [five]])))